This invention relates to ink jet recording apparatus and more particularly to an ink jet recording apparatus of the type which is capable of adjusting the vertical and transverse spacings between dots formed by such apparatus.
In an ink jet recording apparatus having a printing head provided with a plurality of ink jet nozzles, such as a dot printer, dots are formed on a printing surface by ink ejected through the nozzles while the printing head is moved. In ink jet recording apparatus of the prior art, it has hitherto been possible to effect adjustments of the transverse spacing between the dots on the printing surface by electrically controlling the printing timing. It has also been possible to adjust the transverse spacing between the dots on the printing surface by varying the speed at which the printing head is moved in scanning motion while keeping the printing timing constant. Since it is impossible to vary the spacing between the plurality of ink ejecting nozzles of the printing head, it has hitherto been impossible to adjust the vertical spacing between the dots formed on the printing surface.
If the spacing between the dots on the printing surface is adjusted only transversely, characters and symbols formed by the dots would only have an increased width and present rather an ugly appearance. Thus a difficulty has been experienced in putting into practical use on ink jet recording apparatus of the prior art capable of adjusting the spacing between the dots, because such apparatus is unable to meet the requirement of changing the size of characters and symbols without lowering the quality of the produced characters and symbols.
There has thus been felt a need for an ink jet recording apparatus which enables the size of characters and symbols to be freely varied without in any way distorting the characters and symbols.